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    <title>Document</title>
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    <script>
      //   function sum(...nums) {
      //     let sum = 0
      //     for (const value of nums) {
      //       sum += value
      //     }
      //     return sum
      //   }
      //   console.log(sum(1, 2, 3, 4, 5))

      //   let a = ['lee', 'tom', 'big']
      let a = [1, 2, 3, 4, 5, 6, 7, 8, 9]
      let res = a.reduce((a, b) => {
        return a + b
      })
      console.log(res)
    </script>
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